<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <script>
     //es6继承-先声明父类，在声明子类，通过extends继承方法,通过super()继承属性
    class User{
      constructor(name, pass){
        this.name=name;
        this.pass=pass;
      }

      showName(){
        console.log(this.name);
      }
      showPass(){
        console.log(this.pass);
      }
    }
    
    class VipUser extends User{
      constructor(name, pass, level){
        super(name, pass);  //继承父类上的属性  super指代了整个prototype或者__proto__指向的对象

        this.level=level;
      }

      showLevel(){
        console.log(this.level);
      }
      
    }

    var v1=new VipUser('blue', '123456', 3);

    v1.showName();
    v1.showPass();
    v1.showLevel(); 
    </script>
  </head>
  <body>

  </body>
</html>
